Progress in development of the hydrogeomorphic approach for assessing the functioning of wetlands

Abstract

The hydrogeomorphic (HGM) approach to assessing the functioning of wetlands has been undergoing development for the past 6 years. We describe progress that has been made since presenting the approach at the last INTECOL conference in 1992. The approach is characterized by three interrelated components: classification, articulation of functions, and the use of reference wetland ecosystems. Classification is used to partition natural variability in wetlands so that the assessment can be built around a smaller subset of wetlands that share common structure and functioning. In so doing, classification improves the capacity to separate sources of natural variation from those due to disturbance by human activities. Articulation of functions includes identifying subsets of wetland processes that either are commonly recognized ecosystem functions or functions specific to particular wetland classes. Logic models are developed to depict recognized functions. The models use ecosystem processes and structural components as variables which serve as surrogates for more detailed measurements of structure and function. Reference wetland systems include the knowledge base for a class as well as sites that encompass the range of variability exhibited by the class including undisturbed and altered sites. Reference wetlands provide a scale for indexing the variables and their associated functions to the least altered wetlands of a particular class. These least altered sites allow the identification of reference standards for the variables and represent characteristic levels of functioning on a sustainable basis. The altered wetlands contribute information useful toward the scaling of variables and functions between characteristic levels of functioning and those at lower levels due to alterations. Considerable iteration is necessary among the three components (i.e., classification, articulation of functions, and the use of reference systems) in developing an assessment method for a particular regional group of wetlands. Once the method is developed, however, the assessment process is rapid and repeatable. 394 Wetlands for the Future

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Cite this paper

@inproceedings{Osmond2012ProgressID, title={Progress in development of the hydrogeomorphic approach for assessing the functioning of wetlands}, author={Glen Osmond and D. Alastair Smith and Dennis F. Whigham and Lyndon Chi-Hang Lee and Richard D. Rheinhardt}, year={2012} }